"You must be over 18 to register for an account." and a checkbox label of "I am over 18".

Dance is a physical activity. As a parent/guardian, I give my son/daughter permission to participate and I take full responsibility for any injuries or accidents that may occur.
Permission is granted to Arco City Ballet, to use video recordings and photographs of the participants for educational, promotional and marketing purposes and social media.
I have read this waiver and release of liability, fully understand its terms, and I sign it freely and voluntarily.